仔仔安全卫士demo（二）

第一步：启动tomcat，在tomcat中加入如下json文件

{"version":"2.0","description":"我是最新的，来下载我把","apkurl":"http://192.168.1.103:8080/zaizaimobilesafe-2.0.apk"}

第二步：实现一个函数显示网络访问服务器获取服务器数据的功能函数

private void chackUpdate() {
    /*定义一个消息对象，作为handler的形参进行数据的传递*/
    final Message message = Message.obtain();
    final long startTime = System.currentTimeMillis();
    new Thread(new Runnable() {
        @Override
        public void run() {
            try {
                /*在value文件夹中配置一个config.xml文件，存储服务器的url，便于维护，getString获得，因为R.string.serviceurl代表的是一个整数是数据的一个标识，而不是数据本身*/
                URL url = new URL(getString(R.string.serviceurl));

                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                connection.setConnectTimeout(4000);
                int code = connection.getResponseCode();
                if (code == 200) {
                    /*访问成功*/
                    InputStream is = connection.getInputStream();
                    /*把流转换成string*/
                    String result = StreamTools.readFromStream(is);
                    Log.i(TAG, "联网成功" + result);
                    /*json解析*/
                    JSONObject object = new JSONObject(result);
                    verison = (String) object.get("vsersion");
                    description = (String) object.get("description");
                    apkurl = (String) object.get("apkurl");
                    /*检查是否是新版本*/
                    if (getVersionName().equals(verison)) {
                        message.what = ENTER_HOME;
                        /*版本一致，进入主页面*/
                    } else {
                        message.what = SHOW_UPDATE_DIALOG;
                        /*更新新版本*/
                    }
                }
            } catch (MalformedURLException e) {
                message.what = URL_ERROR;
                e.printStackTrace();
            } catch (IOException e) {
                message.what = NETWORK_ERROR;
                e.printStackTrace();
            } catch (JSONException e) {
                message.what = JSON_ERROR;
                e.printStackTrace();
            } finally {
                long endTime = System.currentTimeMillis();
                /*运行了多少时间*/
                long dTime = endTime - startTime;
                /*让程序停留2秒*/
                if (dTime < 4000) {
                    try {
                        Thread.sleep(4000 - dTime);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                handler.sendMessage(message);
            }
        }
    }).start();
}

定义一个handler用于接收数据

private Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case SHOW_UPDATE_DIALOG:/*显示升级的对话框*/
                    Log.i(TAG, "显示升级对话框");

                    showUpdateDialog();
                    break;
                case ENTER_HOME:/*进入主页面*/
                    enterHome();
                    break;
                case URL_ERROR:/*URL错误*/
                    enterHome();
                    Toast.makeText(getApplicationContext(), "URL错误", Toast.LENGTH_LONG).show();
                    break;
                case NETWORK_ERROR:/*网络错误*/
                    enterHome();
                    Toast.makeText(getApplicationContext(), "网络异常", Toast.LENGTH_LONG).show();
                    break;
                case JSON_ERROR:/*JSON解析错误*/
                    enterHome();
                    Toast.makeText(getApplicationContext(), "JSON解析错误", Toast.LENGTH_LONG).show();
                    break;
                default:
                    break;
            }

            super.handleMessage(msg);
        }
    };

下一遍将给出entryHome函数以及主页面的代码